The present application is related to, and an improvement on, U.S. Pat. No. 6,212,255 issued to Randol E. Kirk, the inventor herein, which patent is incorporated herein by reference in its entirety.
As stated in the aforesaid patent, X-Ray irradiation of blood product is one of the methods approved by the U.S. Food and Drug Administration for providing a product which diminishes the chance of transfusion-induced diseases. For this purpose, the radiation dose and dose distributions that may occur from X-ray sources must be controlled accurately. X-rays are widely used for such purposes since equipment for providing the X-rays is relatively safe, and also, the equipment for providing the X-rays is comparatively inexpensive as compared to the other types of blood purification.
As disclosed in U.S. Pat, No. 6,389,099, it has been established that a low Z (atomic number) high density material such as carbon, graphite, or boron carbide will reflect X-rays, and these reflected X-rays may be utilized to enhance irradiation energy provided to the product, article or material being irradiated.
In a preferred embodiment of the invention a uniform dose of X-ray beam irradiation is provided to blood product contained in blood transfusion bags. The bags is placed in a selected cannister for receiving the X-ray beam, and the system includes two X-ray tubes positioned to irradiate the bags from opposite sides. Importantly, a collar of low Z high density material is placed around the material being irradiated; this causes a portion of each X-ray beam (a portion that normally would not irradiate the material) to impinge on the collar and be reflected back onto the material; thus a larger percentage of the beam energy is utilized. The present invention provides approximately a three times improvement in throughput (actual volume of output per a given time) over the prior art.